Sound processing devices, including hearing aids, assistive listening devices (ALDs) (defined by the Global Medical Device Nomenclature Agency (GMDNS) as being an amplifying device, other than a hearing aid, for use by a hard of hearing person), and consumer audio devices including headsets, headphones, mobile phone handsets, and MP3 players are being used more frequently in noisy environments by people with normal or near-normal hearing as well as people who are hard of hearing or have impaired hearing. Using such sound processing devices, hearing can be enhanced by adjusting the loudness, frequency-shaping, and dynamic properties of the sounds produced by the devices to suit the needs and preferences of the individual listener. Some of these types of adjustments are commonly available in consumer audio devices by means of analogue volume controls and tone controls.
However, the majority of these sound processing devices now use complex digital signal processing which enables a wide variety of adjustments and customisations of device operation, to suit the individual needs and preferences of the user. For example, digital signal processing often includes many or all of: feedback cancellation, dynamic range optimisation, compression, compression “knee points”, maximum output control, adaptive directional microphones, side tone, echo suppression, and the like. Each such process is often controlled by parameters which can be adjusted to customise the device operation to the user. Such device optimisation is referred to as “fitting” the device to the user. At the same time, devices are becoming smaller and do not have the physical space available for the complex controls that would be necessary to make such a wide variety of adjustments. Consequently, sound processing devices increasingly provide for such adjustments to be made by use of an applications program running on a computer. Once a customised solution is settled upon, the necessary settings are downloaded from the computer to the device by a data connection, to suitably control subsequent operation of the device when in stand-alone use.
In the case of hearing aids, fitting requires audiological services which are typically provided by audiologists and/or audiometrists in a clinical setting. Initially the user's audiogram must be obtained so that device customisation can be optimised to that user's actual hearing loss. Determining a user's audiogram is a specialist task carried out by an audiologist in a clinical setting. The audiologists' fitting software for modern hearing aids may manipulate hundreds of parameters that control the operation of the hearing aid, with optimised parameter values downloaded to the device after fitting is complete. To suitably optimise operation of the device by controlling the numerous available parameters typically requires a skilled audiologist, audiometrist, or hearing aid fitter. The cost of such services, whether borne by the user or a public health system, significantly adds to the expense of hearing aids. Moreover, the limited supply of suitably skilled audiologists presents hearing aid users with limited or delayed access to fitting or re-fitting services. For persons in rural areas or in poorer countries, or persons having only mild hearing impairments, these difficulties can prevent use of such services for proper device fitting and/or can prevent device use entirely.
The processing parameters of sound processing devices other than hearing aids are typically configured by the manufacturer prior to sale of the device, in a manner which tailors the device to the needs of the average consumer, rather than customising it for an individual. For some devices, for example some ALDs, a number of preconfigured customisations may be downloaded into the device prior to sale, with the user given a limited choice between the small number of preconfigured customisations.
The sound processing device fitting methods described above suffer from the disadvantage that either a skilled fitter is required to operate the fitting software (as in the case of a hearing aid), or a single ‘average’ fitting or small number of preconfigured customizations is too limited to be well suited to each individual.
Any discussion of documents, acts, materials, devices, articles or the like included in the present specification is for the purpose of providing a context for the present invention, and is not to be taken as an admission that any such matters form part of the prior art base or were before the priority date of each claim of this application common general knowledge in the field relevant to the present invention.
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